package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.conditions.update.LambdaUpdateWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Autowired
    private RedisIdWorker redisIdWorker;
    @Autowired
    private StringRedisTemplate stringRedisTemplate;
    @Autowired
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;

    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

  /*  //阻塞队列
    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
    //线程池
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    //用于需要在依赖注入完成后执行任何初始化的方法。该方法必须在类投入使用之前调用
    @PostConstruct
    private void init() {
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable {
        @Override
        public void run() {
            while (true) {
                try {
                    //获取队列中的订单信息
                    VoucherOrder voucherOrder = orderTasks.take();
                    //创建订单
                    handlerVoucherOrder(voucherOrder);
                } catch (Exception e) {
                    log.error("处理订单异常", e);
                }
            }
        }
    }*/

    //线程池
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    //用于需要在依赖注入完成后执行任何初始化的方法。该方法必须在类投入使用之前调用
    @PostConstruct
    private void init() {
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable {
        String queueName = "stream.order";

        @Override
        public void run() {
            while (true) {
                try {
                    //获取消息队列中的订单信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    //判断消息获取是否成功
                    if (list == null || list.isEmpty()) {
                        //获取失败，说明没有消息，继续下一次循环
                        continue;
                    }
                    //解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //获取成功，创建订单
                    handlerVoucherOrder(voucherOrder);

                    //ACK确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName, "g1", record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常", e);
                    handlePendingList();
                }
            }
        }

        private void handlePendingList() {
            while (true) {
                try {
                    //获取pending-list中的订单信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    //判断消息获取是否成功
                    if (list == null || list.isEmpty()) {
                        //获取失败，说明pending-list没有异常消息，结束循环
                        break;
                    }
                    //解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //获取成功，创建订单
                    handlerVoucherOrder(voucherOrder);

                    //ACK确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName, "g1", record.getId());
                } catch (Exception e) {
                    log.error("处理pending-list订单异常", e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException interruptedException) {
                        interruptedException.printStackTrace();
                    }
                }
            }
        }

    }

    /**
     * 处理订单信息
     *
     * @param voucherOrder
     */
    private void handlerVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        RLock lock = redissonClient.getLock(RedisConstants.LOCK_ORDER_KEY + userId);
        // 无参方式：确保锁在获得时解锁，并且在未获得锁时不尝试解锁
        boolean isLock = lock.tryLock();

        //获取锁失败
        if (!isLock) {
            log.error("不允许重复下单");
            return;
        }

        try {
            proxy.createVoucherOrder(voucherOrder);
        } finally {
            //手动释放锁
            lock.unlock();
        }
    }

    //@Override
    public Result seckillVoucherOld01(Long voucherId) {
        //查询优惠券
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);

        //判断秒杀是否开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
            return Result.fail("秒杀尚未开始！");
        }
        //判断秒杀是否已经结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
            return Result.fail("秒杀已经结束！");
        }
        //判断库存是否充足
        if (voucher.getStock() < 1) {
            return Result.fail("库存不足！");
        }

        Long userId = UserHolder.getUser().getId();

//        synchronized (userId.toString().intern()) {
//            //获取代理对象（事务）
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        }

        //创建锁对象
        //SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
        //获取锁
        //boolean isLock = lock.tryLock(1200);

        RLock lock = redissonClient.getLock(RedisConstants.LOCK_ORDER_KEY + userId);
        // 无参方式：确保锁在获得时解锁，并且在未获得锁时不尝试解锁
        boolean isLock = lock.tryLock();

        //获取锁失败
        if (!isLock) {
            return Result.fail("不允许重复下单");
        }

        try {
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        } finally {
            //手动释放锁
            lock.unlock();
        }
    }

    private IVoucherOrderService proxy;

    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        //生成订单id
        Long orderId = redisIdWorker.nextId("order");
        //调用lua脚本
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString(), String.valueOf(orderId));

        //判断结果是否为0
        int r = result.intValue();
        //不为0，代表没有购买资格
        if (r != 0) {
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }

        //获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();

        //返回订单id
        return Result.ok(orderId);
    }

    //    @Override
    public Result seckillVoucherOld02(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        //调用lua脚本
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString());

        //判断结果是否为0
        int r = result.intValue();
        //不为0，代表没有购买资格
        if (r != 0) {
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }
        //为0，有购买资格，把下单信息保存到阻塞队列
        VoucherOrder voucherOrder = new VoucherOrder();
        Long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        voucherOrder.setVoucherId(voucherId);
        voucherOrder.setUserId(UserHolder.getUser().getId());
        //放入阻塞队列
        //orderTasks.add(voucherOrder);

        //获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();

        //返回订单id
        return Result.ok(orderId);
    }

    @Override
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //一人一单----悲观锁
        Long userId = voucherOrder.getUserId();
        LambdaQueryWrapper<VoucherOrder> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(VoucherOrder::getUserId, userId).eq(VoucherOrder::getVoucherId, voucherOrder.getVoucherId());
        int count = this.count(queryWrapper);
        //判断是否存在
        if (count > 0) {
            log.error("用户已经购买过一次了！");
            return;
        }

        //扣除库存----乐观锁
        LambdaUpdateWrapper<SeckillVoucher> updateWrapper = new LambdaUpdateWrapper<>();
        updateWrapper.setSql("stock = stock - 1").eq(SeckillVoucher::getVoucherId, voucherOrder.getVoucherId()).gt(SeckillVoucher::getStock, 0);
        boolean update = seckillVoucherService.update(updateWrapper);
        if (!update) {
            log.error("库存不足！");
            return;
        }

        //创建订单
        save(voucherOrder);
    }

    @Override
    @Transactional
    public Result createVoucherOrder(Long voucherId) {
        //一人一单----悲观锁
        Long userId = UserHolder.getUser().getId();
        LambdaQueryWrapper<VoucherOrder> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(VoucherOrder::getUserId, userId).eq(VoucherOrder::getVoucherId, voucherId);
        int count = this.count(queryWrapper);
        //判断是否存在
        if (count > 0) {
            return Result.fail("用户已经购买过一次了！");
        }

        //扣除库存----乐观锁
        LambdaUpdateWrapper<SeckillVoucher> updateWrapper = new LambdaUpdateWrapper<>();
        updateWrapper.setSql("stock = stock - 1").eq(SeckillVoucher::getVoucherId, voucherId).gt(SeckillVoucher::getStock, 0);
        boolean update = seckillVoucherService.update(updateWrapper);
        if (!update) {
            return Result.fail("库存不足！");
        }

        //创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        Long orderId = redisIdWorker.nextId("order");
        voucherOrder.setVoucherId(voucherId);
        voucherOrder.setId(orderId);
        voucherOrder.setUserId(UserHolder.getUser().getId());
        save(voucherOrder);

        //返回订单id
        return Result.ok(orderId);
    }
}
